On Monday evening, Clarence House announced that a trapped nerve in Camilla's back meant a change to her original programme.

She was due to fly with Charles to eastern Poland on Tuesday to visit a national park and mosque, but was advised the necessary helicopter flights and car journey might aggravate her back problem further.

Instead she remained in Warsaw, visiting the British Embassy in the capital before heading to a museum featuring the life of the composer, Chopin.

Arriving at the embassy she told reporters, "I've just got this trapped nerve and I can't shift it. Its very annoying, you just want someone to pull it out!"

Both the duchess, 62, and Charles have suffered with back problems in the past.

According to the Telegraph, Camilla is being treated by the Prince of Wales' physician, who accompanies the couple on foreign visits.

Husband and wife are on day two of an eight day-long visit to Eastern Europe, which also includes stopovers in the Czech Republic and Hungary.

On Monday evening, they both attended a state dinner in their honour at the presidential palace – pictured - hosted by President Lech Kaczynski.